: I don't have anything other than the photo of Steve C's boat, but I
: suspect the floor is covered on the outside with skin. Adding
: anything on the outside of the skin seems problematic. When I
: attached the rub rails to the gunnels on my SOF
: "Dermie" using screws, the drill grabbed strands of
: the 1050 ballistic nylon while drilling several of the holes and
: made noticeable "pull stripes" across the skin. Doing
: it again, I would be inclined to either A) pre-drill the rub
: rail and spread open the weave under the hole, or B) attach the
: rub rail after coating the skin. As you point out, good reason
: for an inner keel.

Drilling holes in the fabric will be far worse, you don't want to do that. Melting holes though is easy and creates a hard edged hole that will resist the screws from grabbing the weave of the fabric.

An external keel has the advantage of protecting the skin, helpful in a boat heavier than a kayak/canoe etc. where lifting it clear of the water before it grounds will be more difficult.

Bill H.